Database Administrator

Query the character set of the current databaseBYS @ bys1> select userenv ('language ') from dual;USERENV ('language ')----------------------------------------------------AMERICAN_AMERICA.AL32UTF8BYS @ bys1> select * from

1. create data table space, index table space 2. create user jerry and authorize 3. create a table, index, and insert data for user jerry. export data of jerry 5. create user peter and authorize 6. import the data of jerry to the peter user (the

1. Explain the differences between cold backup and hot backup and their respective advantagesAnswer: Hot Backup is applicable to databases in the archive mode. When the database is still in the working state, it is backed up. Cold backup refers to

When xmanager is used for oracle installation in a linux Chinese operating system, garbled interface may appear. You can solve this problem by using the following methods: 1. Modify the environment attribute vi/etc/sysconfig/i18n LANG = "en_US.UTF-8

-- Use the regular expression with t as (select 'guangdong, Guangxi, Hainan, Guizhou, Yunnan 'str from dual) SELECT REGEXP_SUBSTR (str,' [^,] + ', 1, ROWNUM) province FROM tCONNECT by rownum PROVINCE ------------------------------ Guangdong,

I believe everyone has encountered the lock table. I think everyone knows the unlock method, but the killing processes are sometimes low-level. We use stored procedures to implement this function, it becomes very simple. 1. Create a view and query

/* Implemented functions: Use a database to store text data and read it and put it in the current project for analysis: the difficulty is not great. The key is to master the file stream, and there are not many database operations, but the file

It is very convenient for CHAR to store fixed-length data, and the indexing efficiency of CHAR fields is high. For example, if char (10) is defined, no matter whether the data you store reaches 10 characters, it takes up to 10 characters. To store

Aggregate functions for computing in SQL statements: COUNT (*): calculates the number of tuples. COUNT ( SUM/AVG/MAX/MIN (): Calculate the SUM, average, maximum, and minimum values of a column (numeric type) Let's analyze the types of

1. Export the. SQL file, open the doscommand line, run cd to enter the bin directory of mysql, and run Mysqldump-uroot-p your Password Database Name> D:/export file name. SQLFor example: Mysqldump-uroot-p123456 listener> D:/listener. SQL Ii.

The storage engine layer can decide how to lock data by accepting the lock type passed by the Server layer.Table locks are implemented at the Server layer. If MyISAM is not implemented by itself, the table locks passed at the Server layer are used

Database movement is also a common phenomenon. After all, there are various reasons to force us to move. So how can we move faster? See the following. When using an Oracle database, data in the database is often moved from one database to another.

In addition to relying on DBA's personal experience, database optimization also requires the help of some small tools. Recently, the database server is a little slow. Let's see which aspects of the pressure is relatively high! In fact, this Lucky28

To reduce IT complexity and improve data quality, enterprises always want to integrate their businesses to fewer database platforms. However, experts believe that before the database standardization project, pay attention to cultural and technical

BKJIA exclusive Translation: Simple teachingFast scalability Improvement Through several simple rules, we can easily improve the scalability of the MySQL server. One of the following is an instance. "The most effective way to improve SQL statements

Recently, when I first moved to a new company, I suddenly experienced a large volume of interruptions in the production database at night and lasted for nearly an hour. In the event of an accident, I was not at the scene, I missed the opportunity to

Editor's note: many friends may not know where to start when getting started with MySQL's dual-machine synchronization requirements. In fact, this is one of the functions supported by MySQL itself. This article provides a preliminary idea about

I often hear that the most difficult part of SQL Server is performance optimization, which makes people feel mysterious. This kind of thing can only be done by experts. A long time ago, I saw a highly-handwritten blog on the Internet and introduced

This article analyzes the traditional distributed Cache system and points out that it will put a great deal of pressure on the database during Cache reconstruction. It also analyzes how the MongoDB mmap solution avoids this problem. For example, in

The first concern of people who use database replication is the performance consumption of the master server and backup server. I am also very worried about this. After checking for half a day, I basically did not find similar test instructions, I